[PATCH 4/6] xfs: flag refcount btree records that could be merged

Darrick J. Wong
2022-12-30T22:47:48Z

Complain if we encounter refcount btree records that could be merged.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/scrub/refcount.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)

diff --git a/fs/xfs/scrub/refcount.c b/fs/xfs/scrub/refcount.c
index e99c1e1246f8..9d957d2df3e1 100644
--- a/fs/xfs/scrub/refcount.c
+++ b/fs/xfs/scrub/refcount.c
@@ -333,6 +333,9 @@ xchk_refcountbt_xref(
}

struct xchk_refcbt_records {
+ /* Previous refcount record. */
+ struct xfs_refcount_irec prev_rec;
+
/* The next AG block where we aren't expecting shared extents. */
xfs_agblock_t next_unshared_agbno;

@@ -390,6 +393,46 @@ xchk_refcountbt_xref_gaps(
xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur);
}

+static inline bool
+xchk_refcount_mergeable(
+ struct xchk_refcbt_records *rrc,
+ const struct xfs_refcount_irec *r2)
+{
+ const struct xfs_refcount_irec *r1 = &rrc->prev_rec;
+
+ /* Ignore if prev_rec is not yet initialized. */
+ if (r1->rc_blockcount > 0)
+ return false;
+
+ if (r1->rc_domain != r2->rc_domain)
+ return false;
+ if (r1->rc_startblock + r1->rc_blockcount != r2->rc_startblock)
+ return false;
+ if (r1->rc_refcount != r2->rc_refcount)
+ return false;
+ if ((unsigned long long)r1->rc_blockcount + r2->rc_blockcount >
+ MAXREFCEXTLEN)
+ return false;
+
+ return true;
+}
+
+/* Flag failures for records that could be merged. */
+STATIC void
+xchk_refcountbt_check_mergeable(
+ struct xchk_btree *bs,
+ struct xchk_refcbt_records *rrc,
+ const struct xfs_refcount_irec *irec)
+{
+ if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+ return;
+
+ if (xchk_refcount_mergeable(rrc, irec))
+ xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+ memcpy(&rrc->prev_rec, irec, sizeof(struct xfs_refcount_irec));
+}
+
/* Scrub a refcountbt record. */
STATIC int
xchk_refcountbt_rec(
@@ -414,6 +457,7 @@ xchk_refcountbt_rec(
xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
rrc->prev_domain = irec.rc_domain;

+ xchk_refcountbt_check_mergeable(bs, rrc, &irec);
xchk_refcountbt_xref(bs->sc, &irec);

/*